Skip to content
Fencer Vulns
medium 5.5

CVE-2026-46202 json

HID: appletb-kbd: run inactivity autodim from workqueues

published 2026-05-28 5 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-32829

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 2%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

HID: appletb-kbd: run inactivity autodim from workqueues

The autodim code in hid-appletb-kbd takes backlight_device->ops_lock via backlight_device_set_brightness() -> mutex_lock() from two different atomic contexts:

* appletb_inactivity_timer() is a struct timer_list callback, so it runs in softirq context. Every expiry triggers

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:591 Call Trace: <IRQ> __might_resched __mutex_lock backlight_device_set_brightness appletb_inactivity_timer call_timer_fn run_timer_softirq

* reset_inactivity_timer() is called from appletb_kbd_hid_event() and appletb_kbd_inp_event(). On real USB hardware these run in softirq/IRQ context (URB completion and input-event dispatch). When the Touch Bar has already been dimmed or turned off, the reset path calls backlight_device_set_brightness() directly to restore brightness, producing the same warning.

Both call sites hit the same mutex_lock()-from-atomic bug. Fix them together by moving the blocking work onto the system workqueue:

* Convert the inactivity timer from struct timer_list to struct delayed_work; the callback (appletb_inactivity_work) now runs in process context where mutex_lock() is legal. * Add a dedicated struct work_struct restore_brightness_work and have reset_inactivity_timer() schedule it instead of calling backlight_device_set_brightness() directly.

Cancel both works synchronously during driver tear-down alongside the existing backlight reference drop.

The semantics are unchanged (same delays, same state transitions on dim, turn-off and user activity); only the execution context of the sleeping call changes. The timer field and callback are renamed to match their new type; reset_inactivity_timer() keeps its name because it is invoked from input event paths that read naturally as "reset the inactivity timer".

Patch / fix

  • Linux Linux 6.18.32, 7.0.9, 7.1
  • linux Debian 14 7.0.9-1

debian advisories DEBIAN-CVE-2026-46202

  • linux Ubuntu 26.04 LTS 7.0.0-28.28
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1009.9
  • linux-gcp Ubuntu 26.04 LTS 7.0.0-1008.8
  • linux-gke Ubuntu 26.04 LTS 7.0.0-1003.4
  • linux-ibm Ubuntu 26.04 LTS 7.0.0-1010.10
  • linux-azure Ubuntu 26.04 LTS 7.0.0-1010.10
  • linux-raspi Ubuntu 26.04 LTS 7.0.0-1015.15
  • linux-riscv Ubuntu 26.04 LTS 7.0.0-28.28.1

ubuntu advisories UBUNTU-CVE-2026-46202

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-source openSUSE Tumbleweed 7.0.11-1.1

opensuse advisories openSUSE-SU-2026:10954-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-46202 updated

kernel: HID: appletb-kbd: run inactivity autodim from workqueues

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.13% chance of exploitation in the next 30 days, higher than 2% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.